This makes me wonder....
The dv6000 series (and probably others) have an infrared receiver on them to use with a little remote that comes inserted into the thing. Now the IR port isn't exposed as an actual IR device, because pressing buttons on the remote just sends keystrokes, so you can see where this is going...
The dv6000's are pretty common, I see people with them all the time, and although you'd need line of sight to send keystrokes, your target wouldn't need to be using any dongle, just a particular laptop. Now that's scary.
Goes through the list once, and reads like set notation!
(and does i+1 once, which is what I assume you were going for with the separate [i+1 for i in a])
The dv6000's are pretty common, I see people with them all the time, and although you'd need line of sight to send keystrokes, your target wouldn't need to be using any dongle, just a particular laptop. Now that's scary.